libcamera: value_node: Add constructor with value

The new constructor takes a value, allowing creation of a leaf ValueNode
with a value in a single operation instead of having to call set() on an
empty node.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>

include/libcamera/internal/value_node.h

@@ -143,6 +143,14 @@ public:
 #endif /* __DOXYGEN__ */
 
 	ValueNode();
+
+	template<typename T>
+	ValueNode(T &&value)
+		: type_(Type::Empty)
+	{
+		set(std::forward<T>(value));
+	}
+
 	~ValueNode();
 
 	bool isValue() const

src/libcamera/value_node.cpp

@@ -44,6 +44,13 @@ ValueNode::ValueNode()
 {
 }
 
+/**
+ * \fn template<typename T> ValueNode::ValueNode(T &&value)
+ * \brief Construct a ValueNode instance with a value
+ * \tparam T Type of the value
+ * \param[in] value The value
+ */
+
 ValueNode::~ValueNode() = default;
 
 /**